Ackerman et al. Recently demonstrated that high resolution nuclear magnetic resonance (NMR) spectroscopy may be conveniently performed in a sensitive, nondestructive and spatially selective manner on in vivo tissue by utilizing surface coils (Nature, 283, l67-170 (l980). The future implications for the fields of human biochemistry, physiology and medicine appear great. Pursuant to application in these areas the surface coil NMR (SC-NMR) methodology must be developed, critically evaluated, and applied to model animal systems. It is precisely these aims, the development, evaluation, and application of SC-NMR, which form the subject of this proposal. The impetus behind this program is the conviction that SC-NMR will evolve into a powerful probe of in vivo tissue biochemistry with a wide range of applications spanning the basic and clinical sciences. This proposed work seeks to explore and accurately define the potential of this novel spectroscopic approach. Preliminary SC-NMR studies proposed herein concern (i) Cardiovascular Applications, (ii) High-Energy Phosphates in Insulin Action, (iii) Mapping of the Nervous System, and (iv) Tumor Physiology and Pharamacology. These studies are designed to motivate and justify future applications with both animal and human subjects.